1. WEEDS! Paul Benda Argonne Garden Club May 2013

2. 2 Or rather… The cons outweigh the uses.

3. Why are some plants weeds? Most noxious weeds are of Eurasian origin. – Introduced for forage, erosion control, wildlife (Crownvetch). Culinary uses (Garlic mustard). – Accidental contamination of cereal grain supplies (Canada Thistle, Velvetleaf). – Many not considered “weeds” back home (Purslane). Grow early/late compared to natives/crops. Able to grow well where other plants cannot. No major pests, diseases. No major economic uses, just damage. 3

4. Some Useful Weeds Creeping Charlie, Gill-over-the-ground – Glechoma hederacea, perennial, mint family. Beer clarifier & preservative, predates hops. Herbal tea. Cooked & fresh leaf. Leaves high in Vitamin C. Groundcover. Brittle stems root easily. 4

5. Some Useful Weeds Dandelion – Taraxacum officinale, perennial, lettuce family. Single plant can make over 5000 seeds/year. Leaves usually cooked, high in vitamins, minerals. Wine from flowers. Root tea is digestive tonic and diuretic. Roots resist shallow weeding. 5

6. Some Useful Weeds Lambs Quarters – Chenopodium album, annual, beet family. Important food plant in ancient Europe & modern India. Nutritious leaves raw or cooked, similar to spinach. Seeds nutritious, similar to Quinoa. 6

7. Some Useful Weeds Purslane – Portulaca oleracea, annual, purslane (moss rose) family. Widely eaten in Europe & Mexico - nutritious leaves raw or cooked, high in vitamins, Omega-3 fatty acids. Very drought tolerant, can switch to CAM. – Traps CO2 at night, – Converts to malic acid then glucose in day. – Morning picked leaves the most sour. 7

8. Weed Propagation: Roots & Stems Mainly perennials. Very hard to control due to extensive underground reserves. Root: Crownvetch, Canada thistle, bindweed. – Roots may go over 10 feet down. Stem: creeping charlie, quackgrass. – Weave into turf, among cultivated plants. 8

9. Weed Propagation: Seeds Mainly annuals/biennials. Fast growing early in season (cool season). Produce thousands of seeds, usually wind dispersed. Seeds may last to 15-40 years (up to 100 years) in soil. Plenty of seedy perennial weeds (Thistles). “One years seeding makes seven years weeding.” 9

10. The Nastiest Weeds of Argonne Subject to debate by area & gardener. Crownvetch Canada thistle Spotted spurge & purslane Prickly lettuce & dandelion Bindweed Creeping Charlie Quackgrass, orchardgrass & crabgrass. Add yours here… 10

11. The Nastiest at Argonne: Crownvetch Coronilla varia, perennial, bean family. Imported from Europe for erosion control. Extensively planted by US & state government on mine spoils, highway embankments. Roots grow over 10 feet. Seeds last 15 years in soil. 11

12. The Nastiest at Argonne: Canada Thistle Cirsium arvense, perennial, lettuce family. Vast root system stores nutrients. Repeated pulling/mowing to deplete reserves. Prolific seed producer: wind dispersal. 12

13. The Nastiest at Argonne: Spotted or Prostrate Spurge Euphorbia maculata, annual, spurge family. Native to N America. Stems fragile, milky sap irritating to skin. Strong fibrous roots, hard to pull. 13

14. The Nastiest at Argonne: Prickly Lettuce Latuca serriola, annual/biennial. Extensive brittle tap root. High seed production: wind. Gets very spiny with age. Bitter milky sap is soporific and analgesic. 14

15. The Nastiest at Argonne: Bindweed Convolvulus arvensis, perennial, Morning Glory family. Extensive brittle root system. Major agricultural weed. Choking vine produces seed. 15

16. The Nastiest at Argonne: Grasses Quackgrass: creeping perennial, extensive brittle root system. Orchardgrass: bunching perennial, very tough. Crabgrass: warm annual, brittle stems. 16

17. Weed Control: Methods Cultivation, weeding, pulling Trenching, edging Mulch, covering Mowing Chemicals Fire 17

18. Weeding Tools Cultivation: hoe, cultivators. Digging: weeders, trowels, spades, pitchforks. Trenching, edging: flat spades, edgers. 18

19. Hand Pulling is… Labor Intensive …but very effective. 19

20. Weed Control: Edging and Trenching Edging: clean look, best for turfgrasses. Trenching: best for crownvetch, bindweed, quackgrass, orchardgrass. 20

21. Weed Control: Mulching 21

22. Don’t give up! 22